Every year, truck farms, meristem operations and plant cultivators sustain great damage due to organisms that infect sets (e.g. plantlets), young plants, mother plants and seeds, destroying them or rendering them useless. If, for example, viruses enter a cultivation, it can be assumed that 100% of the plants will be damaged. The only option open to the truck farms then is the radical measure of destroying the entire culture.
Specifically active agents are commercially available with which a few phytopathogens can be combated without influencing the vitality of the plant. These agents, designated as pesticides, are systemically effective but usually have only a narrow spectrum of activity.
On the other hand, a significantly broader spectrum of activity is offered by common disinfecting agents based on aldehydes, phenols, halogens, peroxides and quaternary ammonium compounds. If these “surface disinfecting agents” get on the plant or are directly applied to the plant, this always entails irreversible damage to the plant. This means that such disinfecting agents can only be used on working surfaces, positioning surfaces and devices such as, e.g., knives and the like. The surfaces must be freed thereafter from adhering remnants of active substances in order not to endanger the plants during subsequent working steps.
However, a sufficient inactivation is not even assured on surfaces since these agents always exhibit significant gaps in their activity against phytopathogenic organisms.
DE OS 32 27 126 and DE OS 32 29 097 teach that certain combinations of anionic surfactants, aliphatic and aromatic carboxylic acids as well as a few heteroaromatic acids are capable of comprehensively killing off or inactivating viruses, bacteria and fungi without gaps in their activity.
The microbes tested according to the above-cited Offenlegungsschriften and patents were primarily human-pathogenic organisms with a low infectiousness like those recommended as test microbes by, among others, the German Society for Hygiene and Microbiology (DGHM) and the German Society for Veterinary Medicine (DVG).
The application of the teaching to highly infectious and resistant phytopathogenic organisms displayed a microbicidal and virus-inactivating activity that was just as persevering as had already been shown to be the case with the human-pathogenic test germs.
However, further tests for plant compatibility with the same agents regularly resulted in a damaging of the test plants in the form of severe scorching, so that the use on plants appeared to be excluded.
It was surprisingly found that the use of certain acid combinations and surfactant combinations in the presence of glycols overcomes the previous deficiency in the combating of phytopathogenic organisms, and that, when applied directly onto a plant, they retain a pronounced bactericidal, fungicidal and viricidal activity and do not damage the plant cells (roots, stems, leaves, flowers and fruit) in the application concentration.